package com.eatme.core.array;

import org.checkerframework.checker.units.qual.A;

public class Array<E> {

    private E[] data;
    private int size;

    /**
     *
     * @param capacity
     */
    // 构造函数，传入数组的容量capacity构造Array
    public Array(int capacity) {
        data = (E[])new Object[capacity];
        size =0;
    }
    // 无参数构造函数，默认数组的容量capacity=10
    public Array() {
        this(10);
    }

    public Array(E[] arr) {
        data = (E[])new Object[arr.length];
        for (int i = 0; i <arr.length; i++) {
            data[i] = arr[i];
            size= arr.length;
        }
    }

    // 获取数组的元素个数
    public int getSize() {
        return size;
    }

    // 获取数组的容量
    public int getCapacity() {
        return data.length;
    }

    // 返回数组是否为空
    public boolean isEmpty() {
        return size == 0;
    }

    // 向所有元素后添加一个新元素
    public void addLast(E e) {
        if(size == data.length) {
            // throw  new IllegalArgumentException("AddLast failed. Array is Full.");
            resize(2*data.length);
        }
        data[size] = e;
        size++;
    }

    public void addFirst(E e) {
        add(0,e);
    }

    //在数组index位置插入一个新元素e
    public  void add(int index,E e) {
        if (index<0 || index>size) {
            throw  new IllegalArgumentException("Add failed. Require index >= 0 and index <= size.");
        }

        if(size == data.length) {
            // throw  new IllegalArgumentException("Add failed. Array is Full.");
            resize(2*data.length);
        }
        for (int i = size-1; i >=index ; i--)
            data[i+1] = data[i];
        data[index] = e;
        size++;
    }

    // 获取index索引的元素
    public E get(int index) {
        if (index<0 || index>=size)
            throw  new IllegalArgumentException("Get failed. Index is illegal");
        return data[index];
    }

    // 获取数组第一个元素
    public E getLast() {
        return  get(size-1);
    }

    // 获取数组最后一个元素
    public E getFirst() {
        return  get(0);
    }

    // 修改index索引位置元素为e
    void set(int index,E e) {
        if (index<0 || index>=size)
            throw  new IllegalArgumentException("Set failed. Index is illegal");
        data[index] =e;
    }

    // 查找数组中是否有元素e
    public boolean contains(E e) {
        for (int i = 0; i < size; i++) {
            if (data[i].equals(e))
                return  true;
        }
        return false;
    }

    // 查找数组元素e所在的索引，如果不存在元素，则返回-1
    public int find(E e) {
        for (int i = 0; i < size; i++) {
            if (data[i].equals(e))
                return  i;
        }
        return -1;
    }

    // 从数组中删除index位置的元素，返回删除的元素
    public E remove(int index) {
        if (index<0 || index>=size)
            throw new IllegalArgumentException("Remove failed. Index is illagal.");
        E ret = data[index];
        for (int i = index+1; i <size ; i++)
            data[i-1] =data[i];
        size--;
        data[size] = null; // loitering objects != memory leak
        if (size == data.length/4 && data.length/2 != 0)
            resize(data.length/2);
        return ret;
    }

    // 从数组中删除第一个元素，返回删除的元素
    public E removeFirst() {
        return remove(0);
    }


    // 从数组中删除最后一个元素，返回删除的元素
    public E removeLast() {
        return remove(size-1);
    }

    // 从数组中删除元素e
    public void removeElement(E e) {
        int index = find(e);
        if (index!=-1)
            remove(index);

    }

    public void swap(int i,int j) {
        if (i<0 || i >= size || j < 0 || j>= size)
            throw  new IllegalArgumentException("Index is illegal.");
        E t = data[i];
        data[i] = data[j];
        data[j] = t;
    }

    @Override
    public String toString() {
        StringBuilder stringBuilder = new StringBuilder();
        stringBuilder.append(String.format("Array: size = %d, capacity = %d\n",size,data.length));
        stringBuilder.append('[');
        for (int i = 0; i < size; i++) {
            stringBuilder.append(data[i]);
            if (i!=size-1)
                stringBuilder.append(", ");
        }
        stringBuilder.append(']');
        return stringBuilder.toString();
    }

    private void resize(int newCapacity) {
        E[] newData = (E[]) new  Object[newCapacity];
        for (int i = 0; i < size; i++)
            newData[i] =data[i];
        data = newData;

    }

    public static void main(String[] args) {
        Array<Integer> array = new Array();
        for (int i = 0; i < 10; i++)
            array.addLast(i);
        System.out.println(array);
        array.add(1,100);
        System.out.println(array);
        array.addFirst(-1);
        System.out.println(array);
        array.remove(2);
        System.out.println(array);
        array.removeElement(-1);
        System.out.println(array);
        array.removeFirst();
        array.removeLast();
        System.out.println(array);

    }
}
